1. Technical Field.
The present invention relates to a wheel suspension for a vehicle comprising an in the longitudinal direction of the vehicle transverse spring means, such as a leaf spring. The wheel suspension may advantageously be used both for front and rear suspensions.
2. Background Art.
Modern wheel suspensions have become more and more complicated in order to meet increasing demands for a comfortable ride and safe performance. Many known types of wheel suspensions are of the so called multi-link type, which comprise a number of mutually connected pivotable linkages. By using an ingenious design of these linkages it is possible to achieve an almost optimum compromise between, e.g., ride comfort and performance (such as cornering, rolling etc.) in accordance with the desired character of the vehicle. A disadvantage of this type of multi-link suspension is that the number of components, as well as the number of moving parts, are high, leading to higher costs justifiable only for more expensive vehicles. Further, the relatively large number of moving parts, such as ball joints, will eventually result in higher maintenance costs due to wear.
For less expensive vehicles it is desirable to provide a wheel suspension having a simpler design with as few moving parts as possible enabling it to be manufactured at a lower cost, while still fulfilling the requirements of ride comfort and performance necessary for this type of vehicle.
A further problem with known wheel suspensions, such as the currently dominating so-called McPherson-type, is the use of bulky suspension struts with coiled springs, which extend into the engine compartment, luggage compartment or passenger space of the vehicle, taking up valuable space that could be better utilized. The engine compartment in modern cars is often reduced by design limitations, which, together with increasing demand for engine performance, makes it desirable to make maximum use of the available space for the engine and its peripheral equipment. As far as the luggage compartment is concerned, the need for a low and level loading surface without extending struts is obvious.
A further problem with extending suspension struts is that their rigidity and upright position in the engine compartment present a potentially increased risk of injury to the body of a pedestrian, should a front-end collision occur in which the pedestrian strikes the hood of the vehicle. The hood itself, as well as other parts of the vehicle body, has been specially designed to absorb the energy of the collision by means of controlled deformation. At moderate speeds this results in a relatively gentle deceleration of the body of the pedestrian, as compared to the body of the pedestrian striking the relatively rigid suspension struts after an initial deformation of the hood. For this reason it is desirable to eliminate struts of this type from the engine compartment.
The present invention provides a wheel suspension for a vehicle, wherein both the right and left wheels are carried by a linkage having a first and second end section. The first end section is connected to the vehicle on the side of the vehicle opposite its respective wheel, and the second end section is likewise connected to its respective wheel.
The invention is particularly significant in that the linkages are substantially U-shaped, with each having two legs that are mainly parallel and extend in a substantially transverse direction of the vehicle. The free ends of the linkages constitute the first end section. The linkages further have a closed section connecting the legs. The closed section constitutes the second end section, whereby an open space is defined between the legs of each linkage. At least one leg on one of the linkages extends into the open space between the legs of the other linkage.
According to a preferred embodiment of the invention, the legs of one linkage are provided with attachment points on the vehicle that are displaced in the longitudinal direction of the vehicle in relation to corresponding attachment points for the other linkage.
According to a further preferred embodiment of the invention, a leg of one linkage is positioned substantially within the open space of the other linkage. The linkages are pivotably journaled in the vehicle, preferably around axes that are mainly parallel to the longitudinal direction of the vehicle.
The second end section of each linkage is preferably connected to a spring means. The spring means is connected to the vehicle and is preferably a leaf spring placed transverse to the longitudinal direction of the vehicle. The second end section of each linkage is also connected to a shock absorber that is connected to the vehicle.
In an alternative embodiment, the linkages are rigidly connected to the vehicle and are, at least in part, made from a resilient material such as a composite material.
Additionally, according to an advantageous and simple embodiment, a wheel spindle axle is rigidly connected to the second end section of each linkage. Alternatively, the entire wheel spindle is rigidly connected to the second end section.
With the present invention, a simple and cost effective wheel suspension is achieved having fewer component parts and fewer moving parts than a traditional wheel suspension using suspension struts of the so-called McPherson-type. When the wheel suspension of the present invention is used as a rear wheel suspension, a low and level loading compartment is possible as the need for bulky struts has been eliminated. The relatively low number of moving parts also reduces the need for maintenance.
A further advantage with the wheel suspension of the present invention is that it may be used for both the rear and front wheel suspensions. This allows the economical use of many of the component parts in both the front and rear ends of the vehicle.
In summary, the wheel suspension of the present invention is an economically advantageous alternative to more complex wheel suspensions of the so-called multi-link type.